How do I make my subs not change inputdata in Vba excel

Question

When I call a sub and supply a variable, the passed variable is altered after the sub terminates. How can I stop it from doing that?

Debug. print in the example should therefore be 3 rather than 8.

sub main()
  i = 3
  SomeSub i
  debug.print i
end sub

sub SomeSub(j)
  j=j+5
end sub

Answer 1

Use the ByVal keyword to pass on the value

Sub SomeSub(ByVal j As Long)
  j = j + 5
End Sub